For most residences in an urban environment, the treatment of used water is not a problem since the used or wastewater is forwarded directly to a sewage treatment plant through an appropriate collector system. However, in many rural environments, such options are not available and accordingly, it is incumbent on each residence to provide for a wastewater treatment system.
Typically, a residential wastewater treatment system will comprise a septic tank, usually having two compartments, following which the used water is fed to a drainage field wherein it is allowed to slowly percolate into the soil.
Problems arise when local geographic conditions prevent the use of typical drainage tiles. Thus, many residences are located in areas where it is impossible to dig, due to local geological formations, to provide for the drainage field. In such instances, other solutions have had to be adopted including the use of holding tanks and the like.